The invention relates to a memory device comprising at least one memory stack of stacked memory dies which are staggered with respect to each other.
In particular, the invention relates to a flash memory having at least one flash memory stack of stacked flash memory dies which are staggered with respect to each other.
The market demand for smaller, lighter and more powerful cell phones, PDAs and other electronic devices is driving the development of more compact electronic packages with increased functionality. To increase functionality and capacity of electronic devices memory dies are stacked upon each other. Each stack has two, three and four wire bonded dies which are typically arranged in a pyramid or in a stack of same-sized dies with overhanging designs. In this conventional approach, dies are stacked upon each other either with a spacer or with an inter-poser layer in between. Currently, dies having a thickness of around 100 μm are in production. In conventional memory die stacks, the number of dies which are stacked upon each other is restricted because of the constrains of the allowed package height. When stacking dies upon each other, the bonding of the die pads arranged on each die with corresponding pads on a substrate of the memory device becomes difficult and the wire bonding consumes more space with an increased number of dies stacked upon each other. The space consumption for wire bonding increases, in particular, if a pad or a die is bonded to different pads on the substrate. Furthermore, with the increased number of wire bonds, further a risk of visual and electrical shorts is increased.